When a reporter revealed classified information, the source of the 'leak' was investigated.
One of the car's tires has a 'slow leak'. [=a small hole through which air escapes slowly]
Security is high because of a fear of 'leaks' before negotiations have been finished.
(..) We don't have to outrun them long, just long enough. Lighten the ship, stem to stern! Anything we can afford to lose, see that it's lost. Apparently, there's a leak. Haul on the main brace! Make ready the guns! And run out the sweeps. - Pull! - Ho! (..)2003 Pirates of the Caribbean: The Curse of the Black Pearl